title: The role of Med19 in the proliferation and tumorigenesis of human hepatocellular carcinoma cells.
abstract: OBJECTIVE
  To explore the role of Med19, a component of the Mediator complex that coactivates DNA-binding transcription factors, in the proliferation and tumorigenesis of human hepatocellular carcinoma cells.
  
  
  METHODS
  The human hepatocellular carcinoma cell lines HepG2 and Hep3B were infected with lentiviral vectors encoding interfering RNA (RNAi) targeting the Med19 gene. To further confirm the inhibitory effects of RNAi vectors on Med19 gene expression, quantitative real-time RT-PCR and Western blotting assays were used. The proliferation of HepG2 and Hep3B cells after transduction with the Med19-RNAi-Lentivirus vector was evaluated by MTT conversion, BrdU incorporation, colony formation, and cell-cycle assays in vitro. In addition, the ability of the Med19-RNAi-Lentivirus vector-infected Hep3B cells to form tumors after inoculation into nude mice was determined.
  
  
  RESULTS
  Recombinant lentiviral vectors expressing small interfering RNA (siRNA) against Med19 were constructed and were found to efficiently downregulate Med19 mRNA and protein levels in HepG2 and Hep3B cells. Furthermore, the inhibition of Med19 by RNAi dramatically reduced hepatocellular carcinoma cell proliferation, induced cell-cycle arrest in the G(0)/G(1) phase, and suppressed tumor formation.
  
  
  CONCLUSIONS
  These results provide new evidence of an important role for Med19 in the development of hepatocellular carcinomas, suggesting that lentivirus-mediated RNAi to target Med19 is a potential tool for inhibiting cancer cell proliferation and tumorigenesis.
authors.affiliation: General Surgery Department, Shanghai Jiao Tong University Sixth People's Hospital, China.
authors.forename: Shao-wu
authors.initials: SW
authors.lastname: Zou
authors.forename: Kai-xing
authors.initials: KX
authors.lastname: Ai
authors.forename: Zhi-gang
authors.initials: ZG
authors.lastname: Wang
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yuan
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005822:Genetic Vectors; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D056892:Mediator Complex / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: C558319:MED19 protein, human; D056892:Mediator Complex; D034741:RNA, Small Interfering